In recent years, responding to a demand of reduction of expenses and time for business trips, television conference systems have spread as an example of a transmission system that conducts a television conference via a communication network, such as the Internet. In such a television conference system, the various types of data, for example image data and audio data are transmitted/received between the television conference terminals as an example of transmission terminal to realize the television conference.
Furthermore, in the conventional television conference system, control associated with start or termination of communication among the television conference terminals is executed using a transmission management system (see Patent Document 1 Japanese Patent Application Laid-Open Publication No. 2012-50063, which is incorporated herein by reference in its entirety). In this case, when the control associated with the start of communication has been executed, the transmission management system manages the state of the television conference terminal by updating the state of the television conference terminal during the communication, for example. A user of the television conference terminal can recognize the state of the television conference terminal based on information managed by the transmission management system. Therefore, the start of communication can be requested at a proper timing.
However, conventionally related transmission system executes the control associated with communication in one transmission management system. Therefore, if a lot of the timing of communication occur at the same time, the single transmission management system should control a plurality of connections between the transmission terminals and the relay devices. As a result, that leads significantly increase of the load applied to the one transmission management system. In a case where the loads are dispersed by providing a plurality of transmission management systems, a transmission management system cannot manage a state of a transmission terminal changed by control when the control associated with communication is executed by another transmission management system. In this case, a user of a transmission terminal cannot recognize the state of a destination candidate television conference terminal based on information managed by the transmission management system. Disadvantageously, the start of communication cannot be requested at a proper timing.